1. Field of the Invention PA1 2. General Background
The present invention relates to drill guides used in orthopedic surgery, and more particularly to a drill guide apparatus and method for guiding the placement of external fixation pins in the bone of a human limb to avoid an implanted intramedullary nail, wherein a handle attaches to the nail and a drill guide body adjustably connects to the handle so that the position of the drill guide body can be selected to place selected diameter drill sleeve(s) through the body and against the bone tissue.
Limb lengthening and bone transport are often performed with external fixation devices that fix separate bone segments and then displace the bone segments axially. Bone lengthening procedures are performed with a variety of external fixation devices and the success of these procedures is influenced by the mechanical stability of the lengthening system used.
When an intramedullary nail is used in conjunction with the external fixation device the stability of the lengthening system is greatly increased and the success of the lengthening system is enhanced. The external fixation frame is applied after the nail is implanted in the intramedullary canal of the bone being lengthened. The external frame is connected to the bone with various pins and wires and in connecting the frame to the bone it is necessary to place the pins and wires in the bone allowing for adequate bone purchase but without coming in contact with the implanted nail. Presently, the only way to miss the implanted intramedullary nail, when placing the fixation pins and wires in the bone, is by free-handing the insertion of the pins and wires with image intensification.
Drill guides currently available are for guiding bone screws through implanted intramedullary nails for securing the nail in the intramedullary canal of a bone. These drill guide are connected to the implanted intramedullary nail and aid the surgeon in aligning the drill bit with the preformed holes in the intramedullary nail.
With many intramedullary nail drill guides, a handle or some other device is aligned and securely fastened to the exposed proximal end of the implanted intramedullary nail. A second section of the drill guide has guide holes that align with the screw holes in the implanted nail when the guide is placed in proper alignment on the handle. The orientation of the drill guide insures that the holes drilled into the bone will align with the holes in the intramedullary nail for the proper placement of the bone screws.
It would be advantageous to have a radiolucent or radiotransparent drill guide for use in the placement of pins and wires connecting an external fixation frame to a bone that avoids an implanted intramedullary nail. It would also be advantageous to have a drill guide for the placement of bone pins and wires that could be used with any intramedullary nail and external fixation system that allows adequate bone purchase while avoiding the implanted intramedullary nail.
A PCT application (WO 93/11713) relates to a pilot device for a drill for making the drilling for the insertion of a screw in the neck of a femur, an intramedullary nail being already inserted in the femur. The apparatus includes a pivotable drilling template adjustable for height removably fitted at the proximal end of the intramedullary nail and having at least two drilling holes at a horizontal distance from each other of at least the diameter of the intramedullary nail.